From owner-svn-src-all@freebsd.org  Mon Nov 13 07:47:44 2017
Return-Path: <owner-svn-src-all@freebsd.org>
Delivered-To: svn-src-all@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id E63D6D7CA6C;
 Mon, 13 Nov 2017 07:47:44 +0000 (UTC)
 (envelope-from delphij@FreeBSD.org)
Received: from repo.freebsd.org (repo.freebsd.org
 [IPv6:2610:1c1:1:6068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id B0C5364A02;
 Mon, 13 Nov 2017 07:47:44 +0000 (UTC)
 (envelope-from delphij@FreeBSD.org)
Received: from repo.freebsd.org ([127.0.1.37])
 by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id vAD7lhH4098904;
 Mon, 13 Nov 2017 07:47:43 GMT (envelope-from delphij@FreeBSD.org)
Received: (from delphij@localhost)
 by repo.freebsd.org (8.15.2/8.15.2/Submit) id vAD7lhHn098903;
 Mon, 13 Nov 2017 07:47:43 GMT (envelope-from delphij@FreeBSD.org)
Message-Id: <201711130747.vAD7lhHn098903@repo.freebsd.org>
X-Authentication-Warning: repo.freebsd.org: delphij set sender to
 delphij@FreeBSD.org using -f
From: Xin LI <delphij@FreeBSD.org>
Date: Mon, 13 Nov 2017 07:47:43 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r325755 - head/sys/kern
X-SVN-Group: head
X-SVN-Commit-Author: delphij
X-SVN-Commit-Paths: head/sys/kern
X-SVN-Commit-Revision: 325755
X-SVN-Commit-Repository: base
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.25
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 13 Nov 2017 07:47:45 -0000

Author: delphij
Date: Mon Nov 13 07:47:43 2017
New Revision: 325755
URL: https://svnweb.freebsd.org/changeset/base/325755

Log:
  Be more careful when doing calculation with request from userland.
  
  MFC after:	2 weeks

Modified:
  head/sys/kern/kern_proc.c

Modified: head/sys/kern/kern_proc.c
==============================================================================
--- head/sys/kern/kern_proc.c	Mon Nov 13 03:41:50 2017	(r325754)
+++ head/sys/kern/kern_proc.c	Mon Nov 13 07:47:43 2017	(r325755)
@@ -1956,7 +1956,7 @@ sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
 	if (error != 0 || req->newptr == NULL)
 		return (error);
 
-	if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
+	if (req->newlen > ps_arg_cache_limit - sizeof(struct pargs))
 		return (ENOMEM);
 	newpa = pargs_alloc(req->newlen);
 	error = SYSCTL_IN(req, newpa->ar_args, req->newlen);